UV Unwrapping is messed up because of a vertex leading into the wrong ending
Yes that is your problem and you can fix it by selecting the stray edge in Edge mode and dissolving it by pressing x and by selecting Dissolve Edges.

Next use knife tool k and draw the missing edges.


Accept the cut by pressing Enter.
Last select the newly created vertices and move them to better location by double pressing g and sliding them closer to the edge.